Dynamo-electric machine



Patented June 5, 1923.

UNITED STATES PATENT OFFICE.

ARTHUR J. BROWN, OF MILV AUKEE, WISCONSIN, ASSIGNOR TO ALLIS-CHALMERS MANUFACTURING COMPANY, OF IYEILHAUKEE, WISGONSIN, A CORPORATION OF DELAWARE.

DYNAMIC-ELECTRIC lvIACHINE.

Application filed August 29, 1918, Serial No. 252,275.

T 0 all whom it may concern Be it known that ARTHUR J. BROWN, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, has invented a certain new and useful Improvement in Dynamo- Electric Machines, of which the following is a specification.

This invention relates in general to dynamo-electric machines and more particularly to such machines having heavy rotating parts.

In large generating units as hitherto constructed and particularly of that type in which the rotor of the machine is in a horizontal plane it has been customary to support said rotor by means of a thrust bearing or other suitable bearing in turn sup ported by a bridge, usually of cast metal, said bridge being in turn supported by the stator casting of the machine. It has been found that owing to the exceedingly heavy nature of the rotor and attached parts such bridges cause distortion of the stator, rendering it more or less elliptical in horizontal crosssection and introducing all of the disadvantageous features of a varying air gap. These disadvantages have been proposed to be somewhat alleviated by constructing the support for the bearing with a plurality of arms instead of using only a single bridge, but this construction is expensive and this is in particular true where the generators are very large. It is an object of the present invention to obviate the difficulties above noted.

Another object of the invention is the provision of a construction in which less metal is used than has been heretofore the case and in which the cost of producing the same, independently of the cost of the metal, is also less. Other objects will appear hereina-fteras the description of the invention proceeds.

The various novel features of the invention will appear from this specification and the accompanying drawings which form a part thereof and all these novel features are intended to be pointed out in the claims.

Fig. 1 is a diagrammatic cross-section of a generating unit embodying the features of the invention.

Fig. 2 is a diagrammatic top view of the floor of a power house showin the relation of one generating unit to anot er.

Renewed November 10, 1922. Serial No. 600,188.

The prime mover of the generating unit is, in the present case, shown as a hydraulic turbine 1 having a runner 2 located in the wheel pit 3. The runner shaft is drivingly connected to the rotor 5 of the generator through the shaft 7. The weight of the runner of the hydraulic turbine and of the rotor of the generator is supported by the thrust bearing 8 which. is in turn supported by the bridge or arch 9. The stator 6 of the generator is located, generally speaking, in the generator pit 11 and rests on the bottom 12 of said pit. The Walls 10 of the generator pit serve to support the bridge 9. A suitable guide bearing 13 may'if desired be provided in the bridge 9 for the shaft 7.

14 is a ventilating tunnel through which air may be taken from the outside air and led to the wheel pit from where it is thrown out through the generator by means of the fans 15 or any other suitable means.

It will be noted that with the construction in Fig. 1 it is impossible for the weight of the rotor of the prime mover and of the rotor of the generator to transmit any distorting stresses to the stator of the generator for the reason that this weight is supported by a bearing or means in turn supported by means other than the stator of the said generator. The bridge or arch 9, as indicated by the fragment broken away,

is here shown as of a concrete construction,

This construction will clearly result in a saving of metal formerly necessary in heavy bridges of this type. It is however apparent that as far as the feature of this invention is concerned which prevents the transmission of distorting stresses to the stator of the generator, it is not essential that the bridge should be built of concrete and that it can be made of metal as heretofore. When made of metal it may be supported or held in place in any suitable manner, as by foundation bolts, on the walls 10 of the generator p1t.

WVhere several generating units are to be built into a power house as shown, for example, in Fig. 2, the bridges 9 may be built in spaced relation at such a distance from each other that with any given generator in place one half of the stator androtor of any other generator may be lowered into the generator pit and moved into cooperative relation with the shaft 7 and the other half of the rotor and stator. As shown in Fig.

2 enough clearance may be provided between any given generator and the bridge of the other generator so that the above may be accomplished. It is clear however that Where the bridge or arch is not of concrete, not so much clearance between the generators is necessary, as the bridge or arch may of course then be lowered over the shaft 7 after the rotor and stator partshave been assembled.

For the sake of brevity the term concrete has been used in the claims not broad enough to include a metallic bridge or arch, but it is to be understood that the term concrete may include any similar construction such as, for example, a masonry bridge or arch.

It should be understood that it is not desired that the' invention claimed be limited to the exact details of construction shown and described for obvious modifications wil occur toa person skilled in the art.

It is claimed and desired to secure by Letters Patent:

1. In combination, a dynamoelectric machine having' a rotorand a stator, base for said stator, a thrust 'bearingtor said rotor above said machine and a bridge or arch supported bysaid base for supporting said bearing.

2. In combination, a dynamo-electric machine having a rotor and a stator, a concrete base for said stator, aconcrete super-structure forming'an extension of said base and a thrust bearing for said rotor'supported by said super-structure.

3; In combination, a concrete structure forming a pit, a dynamo-electric machine in said pit having a rotor, a wheel pit in said structure beneath said first pit, a runner in said pit drivingly connected with said rotor, a concrete bridge or arch over said first pit,

and a thrust bearing for said rotor supported by said bridge or arch.

4. In combination, a dynamo-electric machine having a rotor and a stator, a concrete structure forming a pit on the bottom oif which pit said stator is supported, a bearing for said rotor, and a super-structure for supporting said bearing supported by the walls of said pit.

5. In combination, a dynamo-electric machine having a rotor and a stationary magnetic-flux-carrying member, a concrete structure having a ledge for supporting said 1nagneticflux-carrying member, a thrust bearing for said rotor above said machine, and a bridge or arch supported directly by said concrete structure for supporting said bearing.

6. In combination, a dynamo-electric machine having a rotor and a stationary magn'etic-flux-carrying member,a concrete structure having a ledge for supporting said magneticdiux-carrying member, and a concrete bridgeor arch supported directly by said concretestructure for supporting said bearing.

7. A hydroelectric generating unit including a concrete structureforming a housing the walls of said housing having a ledge, a stationary magnetic-fluxrarrying' member supported by' said ledge and forming part of the electrical generator otsaid unit, a rotor for said generator, a hydraulic runner in said housing beneath and drivingly connected with said rotor, a thrust bearing for said rotor above said generator, and a bridge or' arch supported directly by said concrete structure for supporting said bearlng, v

In testimony whereof, the signature of the inventor is affixed hereto.

ARTHUR J. BROWN; 

